The present invention relates to devices for dispensing, injecting or delivering substances, and to methods of making and using such devices. More particularly, it relates to a dose-metering mechanism for an injection device, including a metering mechanism by means of which a dose or quantity of a substance to be dispensed from or with the aid of the injection device can be set.
Document DE 202 09 051 U1 discloses an injection device with a dose-setting element blocked in an end position and the injection device has a dose-setting element which, in order to select the product dose, is able to effect a rotating movement relative to the housing in a first direction of rotation as far as an end position and in an opposite direction of rotation, and is coupled with a drive mechanism, by means of which a selected product dose is dispensed from a reservoir, so that the drive mechanism dispenses the product dose selected by the dose-setting element when operated. An anti-rotation lock prevents the dose-setting element from rotating beyond an end position in the first direction of rotation.
Patent specification EP 0 828 527 B1 discloses an injection device with a longitudinally displaceable driving sleeve, provided with printed doses so that a reading can be taken of the dose to be injected and a mechanism which prevents the injection device from being loaded when a push rod is pulled out if the supply of an ampoule has completely run out, and the dose-metering device provides a reading on a dose scale disposed in the region of a top end of the driving sleeve indicating an actual possible dose which can be administered.
German patent application No. 10 2005 001 159.4 discloses a dose-metering device for an injection device with a multiplication ratio, which in particular enables a small dose quantity to be set exactly and dispensed.
Patent specification WO 2004/078239 A1 discloses a device for administering medicaments with a housing incorporating an internal thread, a dose selection sleeve with a thread which engages in the internal thread of the housing, a rotating sleeve which is releasably connected to the dose selection sleeve, and a coupling disposed between the dose selection sleeve and the rotating sleeve, and the two sleeves are able to rotate relative to the housing when the dose selection sleeve and the rotating sleeve are coupled. When the dose selection sleeve and the rotating sleeve are uncoupled, the dose selection sleeve is able to rotate relative to the housing, whereas the rotating sleeve is prevented from rotating relative to the housing, thereby permitting an axial movement of the rotating sleeve so that a force is transmitted in the longitudinal direction to the proximal end of the medicament administering device.